Load-controlling device.



. G. 11.111011111111s. LOADGONTROLLING DEVICE.

ArrLIouioN'rILnDooT.1a,1911.

y1111111111911 May 27,1913.

' 2 SHEETS-SHEET l.

G. M. RICHARDS.

LOAD coNTRoLuNG DEVICE.

. APPLICATION FILED OGT.18, IMI4 y Patented May 27, 1913.

2 SHEETS-SHEET 2.

o NUNITEDi STATES PATENT OFFICE.

GEORGE vM. EIcHAEDs, or ERIE, PENNSYLVANIA.

LoAncoNTRoLLING DEVICE.

' Application led October 18, 1911. lSerial No. 655,272.

To all wjwm t may concern Be it known that GEORGE M. RICIIARDS, a lcitizen yofthe United States, residing at Erie, in the county of Erie and State of Pennsylvania, have invented a new and useful Improvement in Load-ControllingDevices, of which the following is a specification. r

'Ihis invention relates to load controlling deviceswhich are used in connection withuid compressors or pumps for permitting the machine 'to start without lo'ad and for automatically loading the machine after the same reaches the desired speed, and for controlling the pressure of the pumped fluid While the machine is running. f

The device is primarilyintended for use on motorv driven compressors, but is adapted for use with other types of compressors.

In starting a fluid compressor or pump, especially one which is driven by an elec-` tric or other motor havin-g a low starting torque, it is desirable to have the machine `unloaded until it attains nearly its normal running speed, after which the load can be applied, and also-to unload the machine when the pressure ofthe pumped fluidin the receiver reaches a desired maximum.

The objects ofthis invention are to provide a load controlling device which willautomatically load the machine aftenthe desired speed has` been attained and which will unload the machine when the pressure of the pumped fluid reaches thel desired maximum; also'to produce a device of this kind which is simple in construction and4 reliable 1in operation and which is readily adjust-able to adapt the device to operate under various. different conditions; also to provide means by which the machine, while in operation, can be unloaded at any time. vInthe accompanying drawings consisting of two sheets: Figure 1 is an elevation of j an unloading device embodying the :invention. Fig. 2 isa sectionalelevation thereof on line 2 2, Fig. l. Fig. 3 v:is a -fragmentary sectional elevation thereof on 4an en larged scale, on line 3 3, Fig. 2. Fig. is

f a sectional elevation thereof on line 4- 4,

F 1g. 2. Y

Like reference characters refer to like parts in the several figures.

The load controller forming the subject l of this invent-ion is especially suited for use Specincation of Letters Patent.

` Patented May 27, 1913.

on air compressors, and the word air will be hereinafter used to designate the pumped iuid, but it is not intended there-- by to limit the invention to air compressors.

A represents the casing of the load controlling device, which may be of any suitable construction and which. has an inlet opening a 4through which the air from the compressor enters the casing, and an outlet opening a', through which the air passesto -receiver or discharge pipes ofthe system.

The outlet opening a" is preferably controlledby a suitable check valve a2 for re-v taining the pressureinthe receiver or dis'- cha-rge pipe. The check valve shown has a.. stem which'is guided inpa cross bar a3, eX'-.

tending across the olftlet connection of the casing.V The casing is also provided, be-v tween its air inlet and outlet openings, with a suitable escape or exhaust opening a* leading to the atmosphere. In the construction shown, the casing is provided with a lateral extension. a5, in which the escape opening a4 is formed, When the air is allowed to pass 'from `the compressor through the escape opening to the-atmospl1ere, the machine is unloaded, and in Vorder to load the machine,

it is necessary t-o close the discharge open-V A for opening and. closing the escape open ng, in the construe-- valve is seat-ed, the aircannot pass through the extension a5 -a'nd through the, escape opening a4 and, therefore, passes around the cylindrical portion b of the casing and past the check valve a2 to the '"receiven The valve B is adapted to be seated byair pressure acting on the inner end of the valve in the valve cylinder b. Air is admitted to the cylinderb for actuating the load controlling valve B by a suitableby-pass or passage' `.connecting the inner end of the cylinder with the inlet end of the casing A. In the construction shown, this bypass consists of a pipe c leading from the inlet connect-ion of the cashing A to a valve chamber c which connects by a passage c2 with the valve cylinder b. This valve chamber is formed in the lower end of a casing or frame C which is fixed to the casing A, for instance by a threaded nipple c3 screwed into a hole in' the casing A. The movement of the load controlling valve by the air pressure is opposed by. a suitable spring D which operates to unseat the valve when the pressure' in the cylinder b drops below a predetermined point. In the construction shown, thisl spring surrounds a tubular stem al which is preferably rigidly secured to the valve B and slides on a rod d 'secured in the extension a5 of `the casing A. The outer end of the spring bears against a dog d2 which has a screw threaded engagement with a threaded portion of the rod d', and is held from turning by two beads or ribs d3 formed in the extension a5 of the casing A. The rod d projects loosely through a hole in the eXtension a5 and a collar or nut d, secured to the rod, limits the outward movement of the rod. The outer end of the rod is slotted or otherwise fashioned to receive a suitable tool for turning it and is provided with a lock nut (Z5 for holding it when adjusted. By turning the rod, the dog (Z2 can be moved toward or from the valve B, thereby regul` lating the compression of the spring. By means of this adjustment, the valve B can be made to seat and load the machine at various different pressures of air acting thereon.

When the compressor is started, the parts lof the load controlling device are in th'e po- A air inlet opening of the casing to be under greater pressure than air at the escape opening adjacent to the valve B. The pressure at theinlet opening is communicated to the valve B through the Vby-pass c leading to the valve cylinder b, and when this pressure is pheric pressure acting on the outer face of the valve B, and 'for effecting variations in A this difference of pressures tocause the valve ntooperate to load the machine at one or located in the inlet connection of the casing A and secured to a pin e, pivoted in the casing. The pin c preferably extends out of the casing to permit the damper to be adjusted, and is provided with a lock nut e whereby the damper can be set in 'any desired position. The pressure in the inlet connection of the casing A and in the valve cylinder b can be varied for a given speed of the compressor by adjusting the damper E to more or less obstruct the inlet connection. Since the pressure in the inlet connection of thecasing and the valve cylinder b varies with changes in the speed of the compressor, the speed at which the machine is to be loaded can lie-controlled either by an appropriate adjustment of thedamper AE or of the spring D for the valve B.

The means for unloading the compressor vwhen the pressure in the receiver reaches a predetermined maximum are constructed as follows: The upper part of the casing or frame C is provided with a cylinder'f in which a piston F is adapted to slide. The air from the receiver is conducted to the up,- per part of the cylinder f through a pipe f', a suitable lter f2 being. preferably inserted between the receiver and the cylinder. The

downward movement of the piston F, due to the pressure in the cylinder f, is transv mitted through a rod f3, slidably mounted in the casing C, to a suitable relief valve Gr which controls a hole in the upper end 0f the valve chamber c', through which the pressure in this chamber andthe cylinder b of the load controlling valve B can be relieved when the relief valve is opened. The relief valve shown is provided with a stem which projects through the relief hole in the valve chamber and is grooved or otherwise shaped to allow the escape of air throughthe relief hole` and with a downwardly projecting 'portion g which is adapted to' close the hole or passage g in the chamber c with which the by-pass pipe c connects, thereby shutting off the admission of air to the valve chamber c and the cylinder b of the load controlling valve B from the inlet opening a of the casing A. lW'hen the airis discharged from the chamber c and the cylinder b, which is con nected therewith, the load controlling valve a yoke h which Abears ag'ainst a collar la," seated' on the lower end of the rod f3. The

other ends of the springs have screw connections with suitable adjusting'screws h2 which bear on arms h3 projecting from the casing-C. 'By meansof the screws k2 the tension of the springs H can be adjusted I .to cause the piston F to be moved to open the .relief valve G by a greater or less press ure of air in the receiver. f

I represents a small vent cock which can be opened by hand to discharge air from the relief valve chamber o at any time during the operatic-n of the compressor and thereby effect the unloading of the machine.

The device described is simple and reliable in voperation and is so constructed that all of the parts thereof are readily accessible and that the device can be ladjusted to'operate at any desired pressure and to `load, the 4 machine `at any speed..

I claim as my invention;

l. -In a load controlling device for :fluidcompressors, the combination of a casing having inlet and outlet portions which connect respectively 'with the compressor and with'a receiver for the compressed fluid, and an escape opening, a check valve located between the escape opening and the receiver for retaining the pressure in the receiver, a valve cylinder located in said casing between said inlet and outlet openings, a load j controlling valve located inv said cylinder land adapted to open and close said escape opening, a by-'pass adapted to transmit fluid Apressure from the inletportion of said casing to said cylinder, whereby theldifierence vbetween the fluid pressures in the inlet portion 'and.the'escape` opening ofthe casing is transmitted to said cylinder to move said 'controlling valve to close vsaid escape opening, and means for returning the contro-lling valve when the pressure in' said cylinder is reduced, 'substantially asset forth.

2. In a load controllingv device for fluid compressors, the .combination of a casing having inlet and outlet portions which connect respectively with the compressor and with a receiver for the compressed fluid, and an escape openinglocated between said inlet and outlet portions, a valve cylinder located in said casing between said inlet and outlet openings, a load controlling valve located in nsaid cylinderand adapted` to open and close said escape opening, said valve being yieldingly held in its open position, and a by pass leading from the inlet portion of the casing'to said cylinder, whereby fluid pressure fr'om'said inlet portion is transmitted to said cylinder 'tolmove said controlling valve to close said escape opening, substantially as s'et forth. 43. In a load controlling device4 for fluid compressors, the combination *of a casing having inlet and outlet portions wh1ch cong with a receiver for the compressed fluid, and

an escape opening, a check valve located between the escape openingand thereceiver gfor retaining the pressure in the receiver', ;a valve cylinder located in said casing be- Itween said 4inlet and outlet openings, a load icontrolling valve located in said cylinder and adapted to open and close said escape lopening, a by-pass adapted to transmit fluid 1pressure from the inlet portion of said casing to`said cylinder, whereby the difference- @between the fluid pressures in the inlet'por tion and the escape opening of the casing gis transmitted to said cylinder to move said controlling valve to close said escape opening, a device located in said casing and adapted to be adjusted to regulate the presfsure in the inlet portion, substantially as set fort-h. l a

4. In a load controlling device for fluid compressors, the combination of a casing having inlet and outlet portions which connect respectively with the compressor and with a receiver for the compressed fluid, Vand an escape opening located between said finl'et and outlet portions, a check valve located between the' escape ojgiening and the .receiver for retaining the pressure in the Ireceiver, a valve cylinder located in said casing between said inlet and outlet openings, a load controlling valve located in said cylinder and adapted to open and close said escape opening, a by-pass leading from the inlet portion of said casing to said cylinder, Awhereby fluid pressure from said inlet portionv lis transmitted to' saidcylinderto move vsaid controlling valve to close said .escape opening, a spring in said casing-forl returnving ythe controlling valve when the pressure in the cylinder Aportion is reduced, and means adjustable exteriorly of said cas'ng forregulating the pressure of said' spring,

substantially as set forth. a

5. In a load controlling device fo/r fluid compressors, the combination of -a casing having inlet and outlet portions which respectively connect with the compressor and with a receiver, and an escape opening located between said inlet and outlet portions, va 'valve'. movable in a cylinder' to open or close said escape opening, a connection between said cylinder and sai'd inlet portion of the casing, whereby thedierence' between the fluid pressures in the inlet portion and the escape opening ofthe casing is transmitted to said cylinder to move said valve to close said escape opening, and means actuated by the pressure of the pumped. fluid foi-discharging the fluid from said cylinder to cause said valve to 'open said escape opening, substantially as set forth. j

6. In a load controlling device for fluid compressors, thev combination of a casing4 having an inlet portion which connects with the compressor, an out-let port-ion leading to a receiver and an escape opening, a check valve located between the escape opening and the receiver for retaining the pressure in the receiver, a load controlling valve located in said casing between said inlet and outlet portions and adapted to open and close said escape opening, means for trans-4 mitting thepressure of the pumped fluid to said controlling valve to move said valve to close said escape opening, means for returning the valve, and means controlled by the pressure of the pumped fluid in the receiver forreducing the pressure acting on said controlling. valve to cause the cont-rolling valve to be moved to open said escape opening, substantially as set forth.

7. In a load controlling device for liuid compressors, the combination of a casing having an inlet portion which connects with the compressor, an escape opening and an outletl opening leading to a receiver, a load controlling valve movable in a cylinder to open and close said escape opening, a connection between said cylinder and said inlet portions of the casing, whereby the pressure of the fluid at the inlet portion is transmitted to said'cylinder to move said valve to 4 close said escape opening,`means for returning the valve to open said escape opening, a relief valve for discharging the fluid from said cylinder, and means actuated by the fluid from the receiver for operating said relief valve, substantially as set forth.

8. In a load controlling device for fluidk compressors, the combination of a casing having inlet and outlet portions which respectively connect with. the compressor and with a receiver, and an escape opening, a valve movable in a cylinder to open or close said escape opening, a connection between said cylinder and said inlet portion of the casing, whereby the pressure of the iuid at the inlet portion is transmitted to said cylinder to move said valve to close said escape opening, and avent cock for discharging the I fluid from saidcylinder to cause said valve to open said escape opening, substantially'as set forth.

9. In a load controlling device for Huid compressors,` the combination of a casing having an inlet portio-n which connects with the compressor, an escape openlng, and an outlet opening leading to a receiver, a load controlling valve movableA in a cylinder to open and close said escape opening, a connection between said cylinder and said inlet .portions of the casing, whereby the pressure of the Huid to the inlet portion is transmitted to said cylinder to move said valve to close said escape opening, means for returning the valve to open said escape opening, a

lrelief valve for discharging'the fluid from said cylinder, means actuated by the fiuid lfrom the receiver for operating said relier'A valve, and a vent. cock for relieving the pressure in said valve cylinder -to ucause said 'f valve to open said escape opening at will, substantially as set forth.

10. In a load controlling device for Huid compressors, the combination of a casing having inlet and outlet openings, which connect respectively with the compressorv and with a receiver for the compressed iuid, and an escape opening, a-check valve'located between the escape opening and the receiver, a

valve cylinder located in said casinglbetween said inlet and outlet portions and extending inwardly from one side of said casing adjacent to said escape opening and which is open at its inner end, a load controlling valve slidably arranged in said cylinder andA having a port-ion which, is adapted to cooperate with a valve seat in said Lcasicng to open and close said escape opening, a bypass leading from the inlet portion of said casing to said cylinder, whereby fluid pressure from said inlet portion is transmitted to said cylinder to move said controlling valve to close said escape opening,and means for returning the controlling valve when the pressure in said cylinder is reduced, substantially as set forth.

11. In a load controlling device for fluid compressors, the combination of a casing having inlet and outlet portions which connect respectively with the compressor and with a receiver for the compressed'fluid,"and

an escape opening, a check valve located between the escape opening and the receiver for retaining t-he pressure in the receiver, a valve cylinder located in said casing between said inlet and outlet openings, a load controlling valve located in said cylinder and adapted to open and close said escape opening, a relief valve chamber connected with said cylinder, anda connection between the inlet portion of said casing and said relief valve chamber, whereby fluid pressure from said inlet portion is transmitted to said Cylinder to move said controlling` valve to close said escape opening, and a'relief valve actuated by the pressure in the receiver for discharging the iuid from said cylinder and for closing said connection between said inlet portion and -the valve chamber, substantially as set forth.

12. In a load cont-rolling device for iuid compressors, the combination of a casing having inlet and outlet portions which connect respectively with the compressor andy with a receiver for the compressed fluid, and an escape'opening, said casing having a lateral extension in whichsaid escape opening is formed, `a valve adapted to engage with a valve seat surrounding .the inner end of said lateral extension, a valve cylinder in which said valve is adapted to slide, a by-pass leading from the inlet portion of the casing to the cylinder for-transmitting Huid pressure from said inlet portion to the'cylinder for seating said valve, a spring extending into said lat-eral extension for unseating said valve, and means operable exterior of said casing for adjusting the compression of .the spring, substantially as set forth. Y

Witness my hand this 16th day of 0ctober, 1911. y

Y GEORGE M. RICHARDS.

Witnesses:

MARION A. RICHARDS, LENA M. PAASGH. 

